view Python/fmod.c @ 16015:c832ef72499d legacy-trunk

This patch introduces an extra pass to the compiler that generates a symbol table for each top-level compilation unit. The information in the symbol table allows the elimination of the later optimize() pass; the bytecode generation emits the correct opcodes. The current version passes the complete regression test, but may still contain some bugs. It's a fairly substantial revision. The current code adds an assert() and a test that may lead to a Py_FatalError(). I expect to remove these before 2.1 beta 1. The symbol table (struct symtable) is described in comments in the code. The changes affects the several com_XXX() functions that were used to emit LOAD_NAME and its ilk. The primary interface for this bytecode is now com_addop_varname() which takes a kind and a name, where kind is one of VAR_LOAD, VAR_STORE, or VAR_DELETE. There are many other smaller changes: - The name mangling code is no longer contained in ifdefs. There are two functions that expose the mangling logical: com_mangle() and symtable_mangle(). - The com_error() function can accept NULL for its first argument; this is useful with is_constant_false() is called during symbol table generation. - The loop index names used by list comprehensions have been changed from __1__ to [1], so that they can not be accessed by Python code. - in com_funcdef(), com_argdefs() is now called before the body of the function is compiled. This provides consistency with com_lambdef() and symtable_funcdef(). - Helpers do_pad(), dump(), and DUMP() are added to aid in debugging the compiler.
author Jeremy Hylton <jeremy@alum.mit.edu>
date Fri, 19 Jan 2001 03:21:30 +0000
parents 6f6f965c5e2d
children 2dea40e40d9d
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line source


/* Portable fmod(x, y) implementation for systems that don't have it */

#include "config.h"

#include "pyport.h"
#include <errno.h>

double
fmod(double x, double y)
{
	double i, f;
	
	if (y == 0.0) {
		errno = EDOM;
		return 0.0;
	}
	
	/* return f such that x = i*y + f for some integer i
	   such that |f| < |y| and f has the same sign as x */
	
	i = floor(x/y);
	f = x - i*y;
	if ((x < 0.0) != (y < 0.0))
		f = f-y;
	return f;
}